$ C{{H}_{3}}-C\equiv H $
The Iupac name of the compound is
(A) Propane
(B) Propene
(C) Propyne
(D) 1 methyl propyne

Hint: The International Union of Pure and Applied Chemistry (IUPAC) has a long history of formally designating organic and inorganic substances. To eliminate duplicate names, IUPAC nomenclature was created so that every chemical may be called using a single set of defined standards. A Guide to IUPAC Nomenclature of Organic Compounds, published in 1900, was the first publication on IUPAC nomenclature of organic compounds, and it featured material from the International Congress of Applied Chemistry.

Complete answer:
Alkynes have the empirical formula $ {{\text{C}}_{\text{n}}}{{\text{H}}_{\text{2n-2}}} $ and are organic compounds with the functional group carbon-carbon triple bonds. They are hydrocarbons that are unsaturated. Alkynes have the suffix –yne, which is used when there is just one alkyne in the molecule, similar to how alkenes have the suffix –ene. When a molecule has both a double and a triple bond, the carbon chain is numbered with the first multiple bond at the bottom. The double bond takes priority if both bonds may be assigned the same number. The molecule is subsequently given the name "n-en-n-yne," with the double bond root name coming first.
Find the longest carbon chain that contains both triple bond carbons. Starting at the end closest to the triple bond, number the longest chain. A terminal alkyne is a 1-alkyne, while alkynes in any other location are known as internal alkynes. Label each of the substituents at its appropriate carbon after numbering the longest chain with the lowest number allocated to the alkyne. Arrange the substituents in alphabetical order while writing down the molecule's name. Use the prefixes di, tri, and tetra for two, three, and four substituents, respectively, if there are more than one of the same substituents. The order of these prefixes is not taken into account.
In $ C{{H}_{3}}-C\equiv H $
The long chain is 3, hence Prop is correct.
Hence propyne is correct (option c).

Note:
The International Union for the Standardization of Nomenclature in Chemistry (IUPAC) is most recognised for its work standardising nomenclature in chemistry, although it has publications in a wide range of research areas, including chemistry, biology, and physics. Standardizing nucleotide base sequence code names, producing publications for environmental scientists, chemists, and physicists, and enhancing scientific education are some of the major things IUPAC has done in these disciplines.